Hi Andrés,

Since the performance requirements are not specified, we may not be able to answer appropriately. If the autopilot in the rudder control system is intended for obstacle and collision avoidance, then a Fuzzy Logic Controller is recommended. If the values of the parameters of the rudder system model are unknown, then a Neural Network System is preferred because the design of a neural network-based control system does not require any prior knowledge about the plant.

For normal steering and navigation, sliding mode control and backstepping control are sufficient. For more info, please refer to Prof. Thor I. Fossen's Handbook of Marine Craft Hydrodynamics and Motion Control.

http://as.wiley.com/WileyCDA/WileyTitle/productCd-1119991498.html

Thanks Mr. Chak. I don't know the parameters of the rudder, but I was reading and searching on the internet and I found that I don't need to know a mathematical model to use a fuzzy controlller.

The goal in this project is to design a rudder control system for autopilot in LabVIEW but I don't have the mathematical model of the ship but I can use any model to design my controller and then I see what happen if I change some parameters of the ship model

Other question, can I use a expert system and slide control for this task?

Dear Mr Gomez,

Even to use the fuzzy controller you need to have some sort of mathematical relationship between inputs and outputs. If this is a class assignment or project do ask your instructor to define some parameters in this regard.

Dear Mr. Gómez,

Designing a fuzzy controller for the ship rudder-yaw is like riding a bicycle in a straight line through an open field. You don't need to know the bicycle dynamics or how much it weighs. All you need to know is to steer right when it sways to the left, and steer left when it sways to the right. This is how you define the rules like an Expert Shipmaster in the fuzzy control system. However, the fuzzy controller should not be your first-line solution to the control problem, when a decent ship model can be derived adequately.

The complete model for any marine craft is a 6-DOF model (surge, sway, heave, roll, pitch and yaw), which is a set of fully coupled equations of motion used for the design and simulation of advanced control system. For maneuvering purpose only, a reduced DOF model with 4-DOF (surge, sway, roll and yaw) can be used. If the rolling motion is unimportant, it is acceptable to formulate the ship maneuvering model as a coupled surge–sway–yaw 3-DOF model.

You are also advised to study Nomoto autopilot model for ship-steering maneuver.

Article Ships Steering Autopilot Design by Nomoto Model

Thanks you very much Mr. Chak, I was looking for this paper for a very long time